1. Field of the Invention
The present invention relates to a silanol condensation catalyst, a heat-curable silicone resin composition for sealing optical semiconductors, and a sealed optical semiconductor using the same.
2. Background Information
Conventionally, epoxy resins have been proposed as resins for use in compositions for sealing optical semiconductors as described, for example, in Japanese Unexamined Patent Application Publication No. H10-228249A. However, there is a problem in that a color of seals formed form compositions including epoxy resin yellow due to heat emitted from white LED elements.
Additionally, organopolysiloxane compositions that cure at room temperature including an organopolysiloxane containing two silanol groups, a silane compound containing two or more hydrolyzable groups in the molecule that are bonded to a silicon atom, and an organic zirconium compound have been proposed as described in Japanese Unexamined Patent Application Publication No. 2001-200161A and Japanese Unexamined Patent Application Publication No. H02-196860A.
Moreover, mixing a condensation catalyst with a diorganopolysiloxane containing two silanol groups and a silane containing three or more alkoxy groups, and then heating the mixture has been proposed as described in Japanese Unexamined Patent Application Publication No. 2007-224089A and Japanese Unexamined Patent Application Publication No. 2006-206700A.